Preparation of amines from metal aryloxides

ABSTRACT

Metal aryloxides in which the metal is an alkali metal, alkaline earth metal, aluminum, zinc, titanium, hafnium, zirconium, boron, lead, or niobium are converted to aryl amines by reaction with either ammonia, primary or secondary amines at temperatures from 200*-500* C.

Inventor Calvin J. Worrel Detroit, Mich.

App]. No. 748,918

Filed July 31, 1968 Patented Dec. 7, 1971 Assignee Ethyl Corporation NewYork, N.Y.

PREPARATION OF AMINES FROM METAL ARYLOXIDES 11 Claims, No Drawings US.Cl 260/581, 260/77.5, 260/243 A, 260/244 R, 260/247,

260/256.4 N, 260/288 R, 260/293 R, 260/298, 260/308 8, 260/309.2,260/319. l 260/3261, 260/326.85, 260/327 R, 260/330.5, 260/335,260/3452, 260/3462 R, 260/465 E, 260/573, 260/576, 260/577 Int. Cl...C07c 85/02, C07c 85/06 [50] Field of Search 260/573, 576, 577, 581

[56] References Cited UNITED STATES PATENTS 2,000,410 5/1935 Morrell etal 260/581 X 3,013,052 9/1935 Horsley 260/581 OTHER REFERENCES Sidgwick,The Organic Chemistry of Nitrogen, (i966), Clarendon Press, Oxford, page144 Primary E.raminer-Charles B. Parker Assistant Examiner- Richard L.Raymond Attorney-Donald L. Johnson ABSTRACT: Metal aryloxides in whichthe metal is an alkali metal, alkaline earth metal, aluminum, zinc,titanium, hafnium, zirconium, boron, lead, or niobium are converted toaryl amines by reaction with either ammonia, primary or secondary aminesat temperatures from 2005'00C.

PREPARATION OF AMINES FROM METAL ARYLOXIDES BACKGROUND The conversion ofhydroxy aromatic compounds such as phenols to the corresponding aromaticamines has been accomplished in the past by such means as the Buchererreaction, in which a hydroxy aromatic is reacted with aqueous ammoniumsulfite or bisulfite. In British Pat. No. 619,877 a similar reaction isshown in which certain phenols are converted to the corresponding amineby reaction with ammonia and ammonium chloride. The reaction is reportedto proceed in fair yield with phenols that are unsubstituted in theirortho positions. However, when attempted with o-substitute phenols onlytrace amounts of amines were produced.

SUMMARY This invention relates to a novel process for replacing anaromatic hydroxyl group with an amine group. Accordingly, an object ofthis invention is to provide a process suitable for converting ahydroxy-substituted aromatic compound to an aromatic amine by replacingthe aromatic hydroxyl group with an amine radical.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This and other objects areaccomplished by providing a process for aminating an aromatic compound,said process comprising reacting a nitrogen compound selected from thegroup consisting of ammonia and amines having at least one hydrogen atombonded to the amine nitrogen atom with a metal aryloxide selected fromthe group consisting of alkali metal aryloxides, alkaline earth metalaryloxides, aluminum aryloxides, zinc aryloxides, titanium aryloxides,hafnium aryloxides, zirconium aryloxides, boron aryloxides, leadaryloxides and niobium aryloxides, at a temperature of from about 200 toabout 500 C.

The metal aryloxides used in the process can be prepared by methodsknown in the art. For example, the corresponding hydroxy aromaticcompound can be reacted with a phenoxide-forming metal reagent. Suitablereagents include the metals themselves, acidic metal halides, metalalkyls and metal alkyl halides. For instance, metallic sodium,potassium, aluminum, calcium, magnesium, strontium, barium and zinc willreact with hydroxy aromatics such as phenols, naphthols,hydroxyphenanthrenes, hydroxyanthracenes andhydroxycyclopentanophenanthrenes by merely mixing the metal with theappropriate hydroxy aromatic and heating to around 200 C. Hydrogen isevolved during the reaction. Preferably the metals are in a high-surfaceform such as granules, powder, turnings or foil. For example, phenolreacts with granular aluminum by merely mixing the two and heating toabout l60 C. Addition of a small amount of mercuric chloride willamalgamate the aluminum and cause the reaction to proceed at lowertemperatures down to around 100 C. Also, alkaline earth metals such ascalcium and magnesium react readily with phenols, naphthols and otherhydroxy-substituted polynuclear aromatics.

As stated above, the acidic metal halides can be used to generate themetal aryloxides. By acidic metal halides is meant the metal halidesusually classified as Lewis acids. For example, zirconium tetrachloride,titanium tetrachloride, hafnium tetrachloride, and the like, react withhydroxy aromatics evolving hydrogen chloride and forming thecorresponding metal aryloxide. when this route is followed the resultantaryloxides sometime retain some of the halogen, but this does notinterfere. For example, an aluminum aryloxide can be prepared by merelyadding aluminum chloride to the hydroxy aromatic and allowing thehydrogen chloride formed to escape. When phenol is used the aluminumphenoxide formed is substantially diphenoxy aluminum chloride. lf somewater is present the phenoxides will be hydrolyzed to some extent. Forexample, if wet phenol is reacted with aluminum metal the resultantaluminum phenoxide will contain some diphenoxy aluminum hydroxide.Preferably the reaction should be carried out under substantiallyanhydrous conditions. There can be some water present but it should notbe sufficient to hydrolyze the metal aryloxide reactant to thecorresponding metal hydroxide.

Another method that can be employed is to react the appropriate metaloxide with the hydroxy aromatic while distilling out the water formed.For example, lead oxide or zinc oxide form lead or zinc aryloxides whenheated with hydroxy aromatics.

Another useful method of making the starting metal aryloxide is to reacta metal alkyl or metal alkyl halide with the hydroxy aromatic. Forexample, metal alkyls and metal alkyl halides such as triethyl aluminum,diethyl aluminum chloride, trimethyl aluminum, methyl aluminumsesquichloride, triisobutyl aluminum, diethyl zinc, ethyl zinc chloride,butyl lithium, amyl sodium, tetraethyllead, tetramethyllead, and thelike, will react with hydroxy aromatics to form the corresponding metalaryloxide. Furthermore, metal hydrides are useful such as sodiumhydride, aluminum hydride, diethyl aluminum hydride, boron hydrides,sodlium aluminum hydride, sodium boro hydride, and the like.

The foregoing methods of making the metal aryloxides from the hydroxyaromatic are not equally applicable to all hydroxy aromatics. They areshown only to suggest typical procedures since metal aryloxides areknown compounds and the methods of preparing them are well-known in theart.

The process of this invention is generally applicable to a broad rangeof hydroxy aromatics since the only reaction site involves the hydroxylgroup bonded to a benzene ring. The rest of the hydroxy aromatic can beanything as long as it does not contain other substituents which arereactive with the metal aryloxide groups formed or which would interferewith the formation of the metal aryloxide reaction site. For example,the aryl portion of the molecule may be a mono-, dior trinuclearradical, or for that matter, can contain even more aryl groups. The arylportion of the hydroxy aromatic may also be fused to other cyclicsystems including heterocyclic systems such as those containing cyclooxygen, nitrogen and sulfur rings. For example, the hydroxy aromatic canbe any of the isomeric hydroxy-substituted derivatives of benzene,naphthalene, anthracene, phenanthrene, indene, isoindene, benzofuran,isobenzofuran, thionaphthene, indole, isoindole,

indolenine, 2-isobenzazole, l,2-benzodiazo|e, l ,3- benzodiazole,indiazine, 1,3-benzoisodiazole, l ,2,3- benzotriazole, benzisoxazole,benzoxadiazole, l ,2-

benzopyran, 1,4-benzopyran, 1,2-benzopyrone, quinoline,

isoquinoline, 1,3-benzodiazine, l,2-benzisoxazine, acenaphthene,fluorene, dibenzopyrrole, xanthene, thianthrene, phenothiazine,phenoxazine, naphthacene,

chrysene, pyrene, triphenylene, and the like, wherein the hydroxyl groupis bonded to a nuclear carbon atom.

The process is also applicable to aryl hydroxy compounds having morethan one hydroxyl radical bonded to a nuclear aromatic carbon atom. Forexample, the process can be applied to such polyhydroxy aromatics ashydroquinones, recorcinols, catechols, l,3-dihydroxy naphthalenes,pyrogallols, phloroglucinols, and the like.

Substituents other than hydroxyl groups may be present in the aromaticcompounds as long as they do not interfere with the course of thereaction. That is to say, the other substituents should be relativelyinert to ammonia, primary or secondary amines, metal aryloxides and thereagent used to convert the hydroxyl groups to metal aryloxides. Forexample, any of the previously listed aromatics may be substituted in avariety of positions with alkyl radicals, aralkyl radicals, cycloalkylradicals, chlorine, bromine, iodine, fluorine, nitro groups, and thelike. A few representative examples of these using the simpler aromaticstructure are p-chlorophenol, pnitrophenol, B-bromo-a-naphthol,B-chloro- 7-hydroxy-coumarone, 2-acetoxy- 7-hydroxy-indolenine,3-n-dodecyl- 7- hydroxy-benzisoxazole, 4-nitro- 8-hydroxy-l,2-benzopyran, 7- secoctadecyl- 8-hydroxy-isocoumarin, and the like.

The reaction proceeds very well when the hydroxy aromatic is ahydroxy-substituted mononuclear aromatic. As previously, these phenoltype materials can be substituted with other groups as long as they donot interfere with the course of the reaction. A preferred class of suchmononuclear hydroxy aromatics are those having the formula:

heptylcyclohexyl)phenol, and 2-sec-pentacontyl hydroquinone.

The advantages of the process over the prior art methods displaythemselves to a greater extent when the hydroxy aromatic is amononuclear phenol in which at least one position ortho to the phenoxideoxygen atom is substituted with a radical selected from the groupconsisting of primary and secondary alkyl radicals containing from oneto 50 carbon atoms, mononuclear aryl radicals containing from six to 20carbon atoms, cycloalkyl radicals containing from six to 20 carbon atomsand primary and secondary aralkyl radicals containing from seven to 20carbon atoms. These are phenols having the formula:

Ra a) wherein p is an integer from zero to two, R is selected from thegroup consisting of primary and secondary aliphatic alkyl radicalscontaining from one to 50 carbon atoms, primary and secondary aralkylradicals containing from seven to 20 carbon atoms, mononuclear arylradicals containing from six to 20 carbon atoms and cycloalkyl radicalscontaining from six to 20 carbon atoms, and R is selected from the groupconsisting of aliphatic alkyl radicals containing from seven to 20carbon atoms, mononuclear aryl radicals containing from six to 20 carbonatoms, and cycloalkyl radicals containing from six to 20 carbon atoms.When reacted with aryloxide-forming metal compounds these phenols formmetal phenoxides which are substituted in the position ortho to thephenoxide oxygen atom. Some examples of the phenolic starting materialsare:

o-sec-butylphenol,

2,5-dimethylphenol,

o-ethylphenol,

2,4,6-trisec-butylphenol,

2,4-dimethylphenol,

2(a-methylbenzyl)phenol,

2-cyclohexyl-p-cresol,

2( 3 ,5 -dite rt-butyl-cyclohexyl )-4-sec-eicosylphenol,

2-sec-pentacontylphenol,

2(a-methyl-4-dodecylbenzyl)phenol,

Z-phenylphenol,

2(4-tetradecylphenyl)phenol,

2(3,5-disec-heptylphenyl)phenol,

2-triacontylphenol,

Z-isopropylphenol,

2,4-disec-dodecylphenol, and

2(a-methyl-4-sec-amylbenzyl)phenol.

An especially valuable feature of this invention is its ability toreplace an aromatic hydroxyl radical with an amine radical when bothpositions on the aromatic nucleus ortho to the hydroxyl group aresubstituted. When the aromatic hydroxy compound is a mononuclear phenolthe'phenolic reactant used in this embodiment of the invention has theformula:

(Rah

I I I wherein q is zero or one, and R and R are selected from the samegroup as R, in fonnula II, and R is selected from the same group as R informula II. Some examples of these phenols are:

2,6-dimethylphenol,

2,4,6-trimethylphenol,

2,6-disec-butylphenol,

2,6-disec-butyl-p-cresol,

2,4-dimethyl-6-sec-butylphenol,

2,6-diisopropylphenol,

2,6-disec-octylphenol,

2,6-di(amethylbenzyl)phenol,

6( a-methylbenzyl )-o-cresol,

2,4-dimethyl-6-(2,3-benzobenzyl)phenol,

2(3-tert-butyl-5-isopropylbenzyl)phenol,

Z-cyclooctylphenol,

2,6-dibornylphenol,

2,6-dicyclohexylphenol,

phenol,

6-sec-pentacontyl-o-cresol,

2,4-dimethyl-6-docosylphenol,

o-phenyl-o-cresol,

2,4-dimethyl-6-(4-tetradecylphenyl)phenol,

2-ethyl-6-( 3 ,S-diheptylphenyl )-p-cresol,

and the like.

The other reactant in the process is either ammonia or an amine havingat least one hydrogen atom bonded to the amine nitrogen atom. These aregenerally referred to as primary or secondary amines. Examples of theseamines are dimethyl amine, methyl amine, ethyl amine, diethyl amine,n-propyl amine, aniline, a-naphthyl amine, piperidine, morpholine,diethanol amine, ethanol amine, n-dodecyl amine, 2-docosyl amine,n-triacontyl amine, l-pentacontyl amine, and the like. Polyamines andpolyalkylene amines are also useful. Examples of these amines areN,N-dimethyl-l,3-propanediamine, ethylene diamine, LG-hexane diamine,diethylene triamine, triethylene tetramine, tetraethylene pentamine, andthe like. When amines having multiple NH or NH groups available are usedthe process can be carried out in a manner to utilize more than one ofthe available amine groups. For example, the reaction of aluminumphenoxide and ethylene diamine can be carried out to form N,N-diphenylethylene diamine. Likewise, 1,6-hexane diamine will form N,N-diphenyl-l,6-hexane diamine. Likewise, tetraethylene pentamine will form a mixturein which the terminal nitrogen atoms are substituted with a phenylradical.

Although the operation of the process is not dependent on knowledge ofthe mechanism, it is thought that the reaction proceeds according to thefollowing equations. For simplicity, aluminum tris phenoxide is used asillustrative of all hydroxy aromatics including all the hydroxyderivatives and all homologs and isomers of the aromatic compoundspreviously listed.

VI Mg(OC H +Nl-l C,,l-l NH C H -,OH+l /lgO VII 2 NaOC l-l NH C H Nl-l-1-C H OH+Na O The above reactions illustrate the process carried out onmetal aryloxides wherein the metals have valences of 1, 2 and 3. Asshown above, not all of the hydroxy aromatic values present as metalaryloxides are converted to amines. Some, according to the aboveequations, is converted back to the starting hydroxy aromatic. This canbe readily recovered and recycled or excess metal aryloxide generatingreagent can be added to raise conversions. The following reaction, inwhich aluminum metal in stoichiometric excess of that required toconvert any phenolic hydroxyl groups to aluminum aryloxides, illustratesthis embodiment of the invention. Vlll 2 A1(OC H +2Al+6Nl-l 6 C H,Nl-l+2Al O +3 H The above embodiment of the invention is readily carried outby mixing excess metal aryloxide generating compound with the hydroxyaromatic when first forming the metal aryloxide from the hydroxyaromatic. The use of excess metal in preparing the metal aryloxides isillustrated by the following equations in which aluminum is reacted withphenol in stoichiometric excess of that required to convert the phenolichydroxyl groups to aluminum aryloxides. IX 2 Al+3 C H OH- Al(OC H,,)-+-Al X 4 AlCl +6 C l- H 3( C l-1,0 AlCl+AlCl +6HCl Xl 2Al(C H +3C H OH-*Al(OC H +Al(C H +3C H The mixtures on the right side of the aboveequations are then merely reacted with ammonia, primary or secondaryamines to form an aryl amine in both high-yield and conversion.

Although in the above illustrations only a relatively few compounds wereemployed, extension of these examples to the broad class of metalaryloxides and amines will be apparent to the skilled chemist based onthe prior discussion. The reaction is basically quite simple andinvolves only the hydroxy radical on the hydroxy aromatic which is firstcon-' verted to a metal aryloxide and a hydrogen atom on ammonia or theprimary or secondary amine. The rest of the molecule is not directlyinvolved and, hence, as long as it does not adversely affect thereaction, can be any of a wide range of aryl radicals. Therefore, it isreadily apparent from the foregoing discussion that the reaction is ofgeneral application to hydroxy-substituted aromatics.

The stoichiometry of the reaction is shown in the above equations. Fromthis, it is seen that from about 0.5 to 1.5 moles of ammonia or amineare required for each mole of metal aryloxide. ln practice, it ispreferred to use an excess of either ammonia or amine as this is thelowest cost material and helps force the reaction to completion. Also,the excess ammonia or amine is readily recovered. A useful range ofammonia or amine is from about 0.5 to 100 moles per mole of metalaryloxide, although greater or lesser amounts can be used withoutadverse effects.

The reaction requires elevated temperatures. The optimum temperaturewill vary somewhat depending on the particular metal aryloxide andnitrogen compound employed. This optimum temperature can be readilydetermined experimentally. In general, the reaction proceeds in thetemperature range from about 200-500 C. A most useful temperature rangeis from 300-450 C.

The reaction is most conveniently conducted under an inert atmosphere ina sealed vessel at the vapor pressure of the reactants at the reactiontemperature. lf desired, the pressure can be increased by introductionof inert gas such as nitrogen in order to keep more reactants in theliquid phase.

Although a solvent is not required, one can be employed when desired. Itshould be relatively inert under the reaction conditions. Suitablesolvents include hydrocarbons, ethers, and the like. Some examples ofuseful solvents are n-octane, benzene, toluene, xylene, mesitylene,diethyleneglycol diethyl ether, diethyleneglycol dibutyl ether, and thelike. In some cases it is advantageous to add some of the anticipatedaromatic amine product at the start of the reaction to act as a solventfor the metal aryloxide.

The process and manner of carrying it out are most readily understood byreference to the following examples. All parts are by weight unlessotherwise specified.

EXAMPLE 1 In a pressure reaction vessel fitted with stirrer and heaterwas placed 240 parts of 2,6-dimethylphenol and 17.8 parts of flakedaluminum metal. The vessel was flushed with nitrogen and sealed. 1! washeated to 245 C. to form aluminum 2,6- dimethylphenoxide and then cooledto 50 C. The hydrogen which evolved in the reaction was vented.Following this, parts of ammonia was added under pressure and the vesselagain sealed. While stirring, the mixture was heated to 350 C., reachinga pressure of 2,400 p.s.:i.g. It was stirred at this temperature for 8hours and then cooled. At room temperature the residual pressure wasvented and the vessel was discharged after adding 1,000 parts of hexaneand 1,000 parts of water. The product showed a 22.11 percent conversionto 2,6-dimethyl aniline and a 72.7 percent recovery of starting2,6-dimethylphenol. This represents an 80.8 percent yield of2,6-dimethyl aniline, based on consumed 2,6-dimethy1phenol.

EXAMPLE 2 This example was conducted in the same manner and using thesame reactants as in example 1 except only 35 parts of ammonia wereused. The pressure at 350 C. was 1,290 p.s.i.g. The product,2,6-dimethyl aniline, was; obtained in good yield.

EXAMPLE 3 In the high-pressure reaction vessel used in example 1 place206 parts of 2,6-ditert-butylphenol and parts of xylene. Flush thevessel with nitrogen and maintain a nitrogen atmosphere while adding asolution of 40 parts of triethyl aluminum in 100 parts of xylene, at35-50 C., over a 1 hour period. Allow the evolved ethane to vent duringthe addition. Stir the mixture at 75-80 C. for an hour, and then cool toroom temperature. Add parts of ammonia under pressure and seal thevessel. While stirring, heat the mixture to 400 C. and stir at thistemperature for 6 hours. Cool to room temperature and vent. Wash withwater and distill the mixture to obtain 2,6-ditert-butyl aniline.

Other hydroxy aromatics can be substituted for the 2,6-ditert-butylphenol in the above example to obtain the correspondingaromatic amine. For instance, a-naphthol yields anaphthyl amine.Likewise, p-chloro-2,6-dimethylphenol forms p-chloro-2,6-dimethylaniline. The following table lists the starting hydroxy aromatic and theproduct obtained when following the above procedure.

Ex. Hydroxy aromatic Aromatic amine product 4..... B-Naphtholfl-Naphthylamine. 5 p-Cresol p-Mothyl aniline. 6.....p-Pontacontylphonol p-Pentacontyl aniline. 7.....o-(a-Mothylbonzyl)phenol. o-(a-lvlethylbenzyl) aniline. 8..2,6-dlcyc1ohexylphonol 2,6'dieyc10hexyl aniline.

2,4,6-tri-tert-l uty1phonol. 2,4,tl-tritert-buty1aniline. 10. 7-hydroxyindcuc 7-mnin0 indeno. 11.. 4,6-dibromo-7-hydroxyindene...4,6-dibron1o-7-amiuoindenc. 1 4-hydroxy benzofuran 4-amino benzofuran.13.. 2-cycl00cytl-p-crcs0l.... 2-cyclooctyl-4anethyl aniline. 14....p-Phonylphenol p-Phenyl aniline. 15.. p-(3,E-di-sec-heptylphenyl)p-(3,fi-di-sec-heptylphenyl) phenol. aniline. 16..p-(l-methylcyclohexyl)phenol... o-(l-methylcyclohexyl) aniline. 17....2-sec-butyl-4,6-dinitr0phenOl... 2-see-butyl-4,6-dinitr0 aniline. 18.2,6-di-sec-buty1phenol 2,6-di-scc-buty1 aniline. 19....2,6'diis0propylphon01. 2,6-diisopropy1 aniline. 20.. 7-hydroxyind01o7-aminoind0le. 21 7-hydroxyl-nitroisobenzoiuran..7-am1'n0-4-nitro-isobenzoiuran. 22.. 4-hydroxy-7'acetoxyindolenine.4-amino-7-acetoxy indolenine. 23.. 7-hydroxyA-methoxy-isothio-7-amino-4-methoxy-isothionaphthene. naphthene. 24....4-hydroxy-benzoisoxazole 4-amino-benzois0xazole. 25.. 7-hydroxy4iodo-benzoisoxazole. 7-amiino-4-i0do-benzoisoxazole. 26.... fi-hydroxycoumarin (a-amino coumarin. 27.... 6hydroxy-S-fiuorocoumarinfi-amino-S-fluorocoumarin. 28-

Z-methyl-a-naphthol 2-methy1a-naphthy1amine. 29..2-0:,-dimet;hylbenzy1)1:1 2-(a,a-dimsthy1benzy1) 1- naphthol. naphthylamine. 30-. 6,8-dichl0ro-B-naphtho1 6,8-(1iphloro-B-naphthyl am no.31.... 2,4-dinitrou-naphthoL. 2,4-(1initro-a-naphthylamino. 32..fl-hydroxy quli1o1ine.. (i-mninor uinolinuv 33.... ii-hydroxyncnmiphtlmno. 4-umin0m'onnphthenn. 34.. 4-hyrlr0xy-7-nmlhyl uuenuph-4-mn1n07-mothyl nvumiph thcnu.

tlicun.

Ex. Hydroxy aromatic Aromatic amine product Ex. Amine reactant Produ t35.... 4-hydroxy-6,8-d1nitroace- 4-amino-6,8-dinitro ace- 76....Diethanol amine N,N4iiethano1naphthyl naphthene. naphthene. amine.36.... 4-hydroxy-6,8-dibromo- 4-amino-6,8-dibrom0 77....-N,Ndimethyl-1,3-propane dia- N,N-dimethyl-N'-naphthylacenaphthene.acenaphthene. 5 mine. 1,3-propane diarnine. 37.... l-hydroxy fiuorenel-amino fluorene. 78.... Piperidine N-naphthylpiperidine. 38....l-hydroxy-2,4-di-sec-amyl 1-amino-2,4-di-sec-amyl 79.... Morpholine-..N-naphthylmorpholine.

fiuorene. fluorene. 80.... Dodecyl amine N-dodecylnaphthylamine. 392-hydr0xy-6,8-difiuoro Ilnorene. 2-amino-6,8-difluoro fluorene. 81...Eicosy1amine...... N-eicosyl naphthyl amine. 40....1-hydr0xy-dibenzopyrr0l Lamino-dibenzo yrrol. 82.... Pentacontyl amineN-pentacontylnaphthyl 41.... 1-hydroxy-2-ethyl-dibenzo-1-amino-2ethylibenzoamine.

pyrrol. pyrrol. 1O 83 Cyclohexylamlne Ncyclohexyl naphthyl amine. 42....1-hydroxy-2,4-diisopropyl 1-amin0-2,4-diis0pr0pyldi- 84....Diacrylonitrile amine N,N-diacrylonitrilc naphthyl dibenzopyrrol.benzopyrrol. amine. 43- a-Hydroxy anthracene a-Amino anthracene. 44-a-Hydroxy-2-phenyl anthracene. a-Amino-Z-phenyl anthraceno. 45-ot-Iy%rti)l12(21,)4di-80- rat-Amino?-(Zfdi-sec-heptylep yp eny antracene. phony ant rracenc. 46- B-Hydroxy anthracene. B-arninoAnthracene. EXAMPLE 85 47 Q-hydroxy anthracene. O-amino anthracene. l5

48. a-Hydrxy-5-dodecy1 an a-Amin o-54iodecyl anthracene. cene. 49-aHydroxy -triacontyl anthraa-Amlno-5-triaeontyl anthran cen e. 50-a-Hydroxy-S-pentacontyl ana-AminoS-pentacontyl anthracene. thracene.

51- a-Hydroxy-ZA-dinitro anthracene.

52. a-Hydroxy-2,4-dich1oro anthracene a-Amino-2,4-dinitro anthracene.a-Amino-2,4-dlchloro anthracene. 3amino ph enanthrene.

53- fl-hydroxy phenanthrene 3-amlno-2ethoxy phenan- 3-hydroxy-2-ethoxyphenanthrone. threne.

55. 3-hydroxy-7-ch1oro phenan- 3-amino-7-chl0ro phenanthrene. threne.

56. 3-hydroxy-8-methy1 phenan- 3-amino-8-methyl phenanthrene. throne.

3-amin0-5-nltro phenanthrene.

2-amino-8-(a-m ethylbenzyD- phenanthrene.

Samino phenanthrene.

S-amino-cyclopentano phononthrene.

l-amino xanthene.

l-amino phenazine.

3ethyI-4,5,7-trlamlno couma- 57- 3-hydroxy-5-nitro phenanthrene.

58- 2-hydroxy-8-(wmethylbenzyl) phenanthrene.

59- S-hydroxy phenanthrene 60. 8hydr0xy-cyc1opentano phenanthrene.

61 l hydroxy xantheue 62- l-hydroxy phenazine 63-3ethyl-4,5,7-trihydroxy courna- 11. mm. 64. 3-n-pr0pyilr-l4,7S-trihydroxy 3-n-propy l-4,7,8-triamino 001111131 coumarm.

65. 3-n-butyl-4,5,7-trihydroxy 3-n-butyl-4,5,7-triarnino ooumarin.coumarin.

66. 3-n-butyl-4,7 S-trihydroxy 3-n-butyl-4,7,8-triamino coumarin.

coumann.

67. 3-phenyl-4,7,8-trlhydroxy coumarin.

68. 3-(1-naphthylmethyD-4 5,7-

trihydroxy coumarin.

69 3-(1-naphthylmethy1)-4,7 8-

trihydroxy coumarin.

71- 4,4-methylenebis(2,6dimethyl- 4,4-methylencbis(2,6-dlmethyl phenol).arnllne) 72. 4,4-bis (2,6-dimethylphcno1) 4,4-bis (2,6-dimethylaniline).

3-pheny1-4,7 S-trlamino couma n.

3-(1-naphthylmethyl)4,5,7-

triamino coumarin.

3-(1-naphthylmethy1) -4,7 8-

triarnino coumarln.

EXAMPLE 73 In the pressure reaction vessel of example I place [44 partsof B-naphthol in parts of magnesium tumings. The vessel is sealed andthe mixture heated to 200 C. to form a mixture of magnesium naphthoxideand unreacted magnesium turnings. After cooling to room temperature theevolved hydrogen is vented and 120 parts of n-butyl amine added. Thevessel is flushed with nitrogen, sealed and, while stirring, heated to450 C. it is stirred at this temperature for 2 hours and then cooled toC. Residual pressure is vented and 100 parts of toluene added. Themixture is stirred, warmed to C. and discharged. The solution is washedwith water and then extracted with hot 20 percent aqueous sodiumhydroxide until the small amount of unreacted B-naphthol is removed. Itis then heated to 50 C. at 2 mm. Hg. to distill out residual water andsolvent, leaving as the product B-naphthyl amine in excellent yield andconversion.

In the above example good results are obtained when equal molequantities of other primary or secondary amines are used in place of then-butyl amine. The following table lists various amine reactants whichmay be substituted in the above example together with the product whichthey will yield.

in the reaction vessel of example 1 place 156.5 parts of 2,6-dimethyl-p-chlorophenol and l00 parts of xylene. Flush the vessel withnitrogen and over a 30 minute period, at 25-30 C., add 123 partsofdiethyl zinc. Stir for 30 minutes at 3035 C., and then heat at 100 C.and stir for l hour. Cool to room temperature and vent. Add 34 parts ofammonia and seal. While stirring, heat to 250 C. and hold at thistemperature for 16 hours. Cool and vent. Discharge into 1,000 parts ofwater, separate the organic phase and distill to recover the product,2,6-dimethyl-4-chloroaniline.

EXAMPLE 86 In the reaction vessel of example I, place 194 parts of 2-hydroxy phenanthrene and 250 parts of toluene. While stirring, heat themixture to 100 C. and under a nitrogen atmosphere add a solution of 160parts of tetraethyllead in 100 parts of toluene. Heat the mixture toreflux and hold a reflux for 4 hours. Cool to room temperature and addparts of ammonia. Seal the vessel and, while stirring, heat to 400 C.Stir at -425 C. for 2 hours and then cool to room temperature. Filterthe reaction mass to remove metallic lead and lead oxide and thenextract with hot concentrated hydrochloric acid. Neutralize the acidextract phase to recover Z-amino phenanthrene.

EXAMPLE 87 In the reaction vessel of example I place 450 parts ofo-tertbutylphenol and slowly add 270 parts of aluminum chloride, keepingthe temperature at 35-40 C. and bubbling nitrogen through the mixtureduring the addition. Over a l hour period, at 3540 C., add I70 parts ofammonia and seal the vessel. While stirring, heat to 400 C. and stir atthat temperature for 4 hours. Cool to room temperature and vent. Washthe reaction mass with 10 percent aqueous sodium hydroxide and distillthe organic phase to recover o-tert-butyl aniline.

EXAMPLE 88 in the reaction vessel of example l place a dispersion of 23parts of metallic sodium in l00 parts of xylene under a nitrogenatmosphere. While stirring vigorously, add a solution of 132 parts of7-hydroxy indene over a 1 hour period, at 35-4O C., allowing the evolvedhydrogen to escape. Stir at 50-60 C. for an hour, or until all thesodium has reacted, and then cool to room temperature. Flush withnitrogen to remove the remaining hydrogen. Seal the vessel andpressurize with 60 parts of ammonia. While stirring, heat to 375 threeand stir at that temperature for 4 hours. Cool to room temperature anddischarge. Filter and wash the filtrate with water. Extract the organicphase 3 times with 500 parts of hot 10 percent aqueous sodium hydroxide.Distill the remaining organic phase under vacuum to recover 7-aminoindene.

Following the general procedure of the above example, other alkalimetals can be employed to convert any of the forementioned hydroxyaromatics to their corresponding amino aromatic. Instead of using themetal dispersion to form the initial aryl oxide it is sometimes moreconvenient to use the alkali metal alkyl such as butyl lithium, amylsodium or amyl potassium.

To the reaction vessel of example 1 add 300 parts of2-(amethylbenzyl)-4-dodecylphenol and 500 parts of xylene. Maintain anitrogen atmosphere and, while stirring, add 38 parts of sodiumborohydride at 35-40 C. over a 1 hour period. Stir at 35-40 C. for anhour, and then at 65-70 C. for 30 minutes. Cool to room temperature andadd 80 parts of ammonia. Seal and while stirring heat to 390 C. and stirat this temperature for 4 hours. Cool to room temperature and vent. Washthe reaction mass with water and extract with hot concentratedhydrochloric acid. Neutralize the hydrochloric acid with sodiumcarbonate to precipitate 2-(a-methylbenzyl)-4-dodecyl aniline.

Other hydrides can be used to prepare the starting aryloxide. Forexample, sodium hydride, lithium hydride, calcium hydride, borohydride,sodium aluminum hydride, lithium aluminum hydride, and the like, can beused with good results.

EXAMPLE 90 To the reaction vessel of example 1 add 264 parts of titaniumcatecholate made by reacting titanium tetrachloride with catechol. Add500 parts of xylene and flush with nitrogen. Seal and pressurize with120 parts of ammonia. While stirring, heat to 400 C. and stir at thattemperature for 2 hours. Cool, vent and discharge. Extract with percentaqueous sodium hydroxide to remove unreacted catechol. Filter theremaining organic phase and distill off the xylene, leaving l,2-diaminobenzene.

Other polyhydroxy aromatics can be used in the process such ashydroquinones, 2,6-ditertbutyl-hydroquinone, pyrogallol, phloroglucinol,and the like.

EXAMPLE 9l To the reaction vessel of example 1 add 980 parts ofzirconium 4-bromo-a-naphthoxide made from tetrabutyl-zirconate and4-bromo-a-naphthol. Add 2,000 parts of xylene and 500 parts of n-dodecylamine. Flush with nitrogen, seal and heat to 375 C. After stirring at375400 C. for 6 hours, cool and discharge. Extract any unreacted4-bromo-a-naphthol with hot aqueous sodium hydroxide and then distilloff the xylene solvent, leaving 4-bromo-a-naphthyl amine.

Following the above procedure, any of the previously described hydroxyaromatics can be converted to the corresponding amine using either thezirconium aryloxide intermediate or other metal aryloxide intermediatessuch as the corresponding hafnium or niobium aryloxides.

The amines made by this process are useful for a variety of purposes.They are intermediates for antioxidants, antiozonants, dyes, herbicidesand insecticides.

The lower molecular weight gasoline-soluble aniline derivatives areuseful antiknock agents for spark ignited internal combustion engines(Ind. Eng. Chem, 47, page 2,141, 1955). For example, N-methyl anilinemade from aluminum phenoxide and methyl amine by the process of thisinvention is an excellent antiknock agent. Likewise, 2,4-dimethylaniline made from aluminum 2,4-dimethyl phenoxide and ammonia is also avery effective antiknock agent. in this use, they are added to a liquidhydrocarbon fuel of the gasoline boiling range in an antiknock amount,generally from 0.25 to 1 percent.

In US. Pat. No. 3,322,810 is described certain 2,6-dialkylisothiocyanates which are useful as pesticides. The isothiocyanates aremade by reacting carbon disulfide with a 2,6-dialkyl aniline. Theseanilines are readily made by the present process. For example,2,6-dirnethyl aniline is made in good yield from the corresponding2,6-dimethylphenol, as shown in example I.

The compounds made by this invention are also intermediates in themanufacture of polyurethanes. These polymers are made by reactingaromatic diisocyanates with polyhydroxy compounds. The diisocyanates arein turn made by the reaction of diamino aromatics with phosgene. The

present invention provides a good process for the preparation of thediamino aromatic from the corresponding d1 ydroxy aromatic. For example,4,4-diisocyanato-3,3',5,5- tetramethyl diphenylmethane is readily madeby either (I) reacting the aluminum aryloxide of4,4-dihydroxy-3,3',5,5'- tetramethyl diphenylmethane with ammonia at200-500 C., or (2) reacting aluminum 2,6-dimethyl phenoxide with ammoniato form 2,6-dimethyl aniline and subsequently coupling this aniline atthe four position through a methylene bridge by reaction withformaldehyde.

1 claim:

1. A process for aminating an aromatic compound, said process comprisingreacting a nitrogen compound selected from the group consisting ofammonia and amines having at least one hydrogen atom bonded to the aminenitrogen atom with a metal aryloxide selected from the group consistingof alkali metal aryloxides, alkaline earth metal aryloxides, aluminumaryloxides, zinc aryloxides, titanium aryloxides, hafnium aryloxides,zirconium aryloxides,, boron aryloxides, lead aryloxides and niobiumaryloxides, at a temperature of from about 200 to about 500 C.

2. The process of claim 1 wherein said metal aryloxide is an aluminumaryloxide.

3. The process of claim 2 carried out at a temperature of from about 300to 450 C.

4. The process of claim 2 wherein said nitrogen compound is ammonia.

5. The process of claim 4 wherein said aluminum aryloxide is an aluminummononuclear aryloxide in which each mononuclear aryloxide group containsfrom six to about 60 carbon atoms.

6. The process of claim 5 carried out at a temperature of from about 300to 450 C.

7. The process of claim 5 wherein said mononuclear aryloxide groups arephenoxide groups substituted in at least one position ortho to thephenoxide oxygen atom with a radical selected from the group consistingof primary and secondary alkyl radicals containing from one to 50 carbonatoms, mononuclear aryl radicals containing from six to 20 carbon atoms,cycloalkyl radicals containing from six to 20 carbon atoms, and primaryand secondary aralkyl radicals containing from seven to 20 carbon atoms.

8. The process of claim 5 wherein said mononuclear aryloxide groups arephenoxide groups substituted in both positions ortho to the phenoxideoxygen atom with a radical independently selected from the groupconsisting of primary and secondary alkyl radicals containing from oneto 50 carbon atoms, mononuclear aryl radicals containing from six to 20carbon atoms, cycloalkyl radicals containing from six to 20 carbonatoms, and primary and secondary aralkyl radicals containing from sevento 20 carbon atoms.

9. A process of claim 1 wherein said metal aryloxide is an aluminumaryloxide of a hydroxy-substituted mononuclear aromatic having theformula:

wherein n is an integer from 0 to 3, m is an integer from 1 to 3, and Ris selected from the group consisting of aliphatic alkyl radicalscontaining from one to 50 carbon atoms, aralkyl radicals containing fromseven to 20 carbon atoms and cycloalkyl radicals containing from six to20 carbon atoms.

10. A process for aminating 2,6-dimethylphenol, said process comprisingreacting ammonia with aluminum 2,6- dimethylphenoxide at a temperatureof from about 200 to about 500 C.

Ill. The process of claim 10 conducted in the presence of aluminum instoichiometric excess of that required to convert any phenolic hydroxylgroups to aluminum aryloxides.

Column 5, line 55, after zg g UNITED STATES PATENT omen;

CERTIFICATE OF CORREC'NON Inventord) Calvin J. Worrel It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

II w

aliphatic alkyl radicals containing from" insert 1-50 carbon atoms,eralkyl radicals containing from Column 5, line 1, insert after 'C I-I=,1\TH

line 2, insert after "NaOC H Signed and sealed this 9th day of May 1972(SEAL) Attest:

EDWARD M.,FLETCHER,JR. ROBERT GOTTSGHALK. Attesting Officer Commissionerof Patents

2. The process of claim 1 wherein said metal aryloxide is an aluminumaryloxide.
 3. The process of claim 2 carried out at a temperature offrom about 300* to 450* C.
 4. The process of claim 2 wherein saidnitrogen compound is ammonia.
 5. The process of claim 4 wherein saidaluminum aryloxide is an aluminum mononuclear aryloxide in which eachmononuclear aryloxide group contains from six to about 60 carbon atoms.6. The process of claim 5 carried out at a temperature of from about300* to 450* C.
 7. The process of claim 5 wherein said mononucleararyloxide groups are phenoxide groups substituted in at least oneposition ortho to the phenoxide oxygen atom with a radical selected fromthe group consisting of primary and secondary alkyl radicals containingfrom one to 50 carbon atoms, mononuclear aryl radicals containing fromsix to 20 carbon atoms, cycloalkyl radicals containing from six to 20carbon atoms, and primary and secondary aralkyl radicals containing fromseven to 20 carbon atoms.
 8. The process of claim 5 wherein saidmononuclear aryloxide groups are phenoxide groups substituted in bothpositions ortho to the phenoxide oxygen atom with a radicalindependently selected from the group consisting of primary andsecondary alkyl radicals containing from one to 50 carbon atoms,mononuclear aryl radicals containing from six to 20 carbon atoms,cycloalkyl radicals containing from six to 20 carbon atoms, and primaryand secondary aralkyl radicals containing from seven to 20 carbon atoms.9. A process of claim 1 wherein said metal aryloxide is an aluminumaryloxide of a hydroxy-substituted mononuclear aromatic having theformula:
 10. A process for aminating 2,6-dimethylphenol, said processcomprising reacting ammonia with aluminum 2,6-dimethylphenoxide at atemperature of from about 200* to about 500* C.
 11. The process of claim10 conducted in the presence of aluminum in stoichiometric excess ofthat required to convert any phenolic hydroxyl groups to aluminumaryloxides.